1. Field of the Invention
The present invention relates to a light-emitting device emitting white light, which is used as, for example, an illumination light source, a light source of a backlight of a liquid crystal display, and relates to a manufacturing method thereof.
2. Description of the Related Art
In recent years, a light-emitting device has been developed which emits white light having a wide emission wavelength interval by combining a light-emitting element which emits ultraviolet light or blue light and phosphors which absorb the light from the light-emitting element and wavelength-convert the absorbed light to emit long-wavelength light. Such a light-emitting device is used as, for example, an illumination light source, a light source of a backlight of a liquid crystal display, and the like. In the application to an illumination light source and a light source of a backlight of a liquid crystal display, there is a demand for white light with low chromaticity unevenness and a high color rendering property.
Conventionally, there has been disclosed a light-emitting device realizing a higher color rendering property by a structure in which two kinds or more of phosphors performing different kinds of wavelength conversion are disposed on a light-emitting element emitting blue light, and the light from the light-emitting element and lights wavelength-converted by the phosphors are mixed (see, Japanese Patent Application Laid-open No. 2001-127346).
FIG. 14 is a view showing the structure of a map light 101 provided in an automobile and including a light-emitting device 100 described in the aforesaid Japanese Patent Application Laid-open No. 2001-127346. A general requirement for the map light 101 used in an automobile is to realize brightness equivalent to 30 lux illuminance or more in a light circle with a 30 cm to 40 cm diameter formed on a map or the like as an object to be illuminated 105 which is, for example, 60 cm apart from the light-emitting device 100. In order to thus realize especially high brightness in a predetermined range in a case where the light-emitting device 100 is used for the map light 101 or the like, light from the light-emitting device 100 is gathered by an optical lens 102.